Aleph

Aleph

[](LICENSE) [](https://www.python.org/downloads/) [](https://pypi.org/project/aleph-rlm/)

Aleph is an MCP server and skill for Recursive Language Models (RLMs). It keeps working state — search indexes, code execution, evidence, recursion — in a Python process outside the prompt window, so the LLM reasons iteratively over large codebases, long-lived projects, logs, documents, and data without burning context on raw content.

+-----------------+    tool calls     +-----------------------------+
|   LLM client    | ---------------> |  Aleph (Python process)     |
| (context budget)|  item.value);
const routeKinds = frequency(
  routes.map((route) => (route.includes('.post(') ? 'write' : 'read')),
  2,
);
const notes = await sub_query_map(
  routes.map((route) => `Explain ${route}`),
  routes,
);
({ routeCount: routes.length, routeKinds, notes })
`, context_id="repo")

Safety Model

Aleph is built to keep raw context out of the model window unless you explicitly pull it back:

• Tool responses are capped and truncated.
• get_variable("ctx") is policy-aware and should not be your default path.
• exec_python stdout, stderr, and return values are bounded independently.
• ALEPH_CONTEXT_POLICY=isolated adds stricter session export/import rules and

more defensive defaults.

• ALEPH_ACTION_POLICY=read-only (or --action-policy read-only) keeps action

tools in read-only mode: search and file loading still work, but writes and subprocess execution are blocked.

The safest pattern is always:

1. Load the large context into Aleph memory.
2. Search or compute inside Aleph.
3. Retrieve only the small result you need.

Docs Map

• [MCPSETUP.md](MCPSETUP.md): client-by-client MCP and skill installation.
• [docs/prompts/aleph.md](docs/prompts/aleph.md): the /aleph and $aleph

workflow plus tool patterns.

• [docs/CONFIGURATION.md](docs/CONFIGURATION.md): flags, env vars, limits, and

safety settings.

• [docs/langgraph-rlm-default.md](docs/langgraph-rlm-default.md): LangGraph

integration with Aleph-style tool usage.

• [examples/langgraphrlmrepoimprover.py](examples/langgraphrlmrepoimprover.py):

repo improvement example with optional LangSmith tracing.

• [CHANGELOG.md](CHANGELOG.md): release history.
• [DEVELOPMENT.md](DEVELOPMENT.md): contributor guide.

Development

git clone https://github.com/Hmbown/aleph.git
cd aleph
pip install -e ".[dev,mcp]"
# Optional extras:
#   .[docs]           -> MarkItDown-backed document conversion
#   .[observability]  -> OpenTelemetry spans
pytest tests/ -v
ruff check aleph/ tests/

References

• Zhang, A. L., Kraska, T., Khattab, O. (2025)

Recursive Language Models (arXiv:2512.24601)

License

MIT

Source & license

This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: Hmbown
• Source: Hmbown/aleph
• License: MIT
• Homepage: https://aleph-web.pages.dev/

Install and usage instructions live in the source repository linked above.